Various types of medical devices employ a needle for piercing the skin of a patient for diagnostic or therapeutic purposes. One such device is a cartridge injector. Cartridge injectors utilize pre-filled cartridges that have a pre-measured dose of medication. The cartridge injector is used to inject the medication from the cartridge into a patient.
Handling of such needle-bearing medical devices after the needle is withdrawn from the patient can result in transmission of various pathogens, most notably human immune virus (HIV), to uninfected medical personnel, due to an inadvertent needle stick. Accordingly, it is desirable to provide a device for injecting medication from a pre-filled cartridge, wherein the injection needle is retracted into the housing of the device after use.